Issue Description Canine herpesvirus (CHV) is a virus of the
family Herpesviridae which most importantly causes a fatal hemorrhagic
disease in puppies (and in wild Canidae) less than two to three weeks
old. It is known to exist in the United States, Canada, Australia,
Japan, England and Germany. CHV was first recognized in the mid 1960s
from a fatal disease in puppies. Other Names Canine Herpesvirus
CHV In Puppies The incubation period of CHV is six to ten
days. CHV is transmitted to puppies in the birth canal and by contact
with infected oral and nasal secretions from the mother or other
infected dogs, but it is not spread through the air. The virus
replicates in the surface cells of the nasal mucosa, tonsils, and
pharynx. Low body temperature allows the virus to spread and infect
the rest of the body. Symptoms include crying, weakness, depression,
discharge from the nose, soft, yellow feces, and a loss of the sucking
reflex. CHV also causes a necrotizing vasculitis that results in
hemorrhage around the blood vessels. Bruising of the belly may occur.
Eye lesions include keratitis, uveitis, optic neuritis, retinitis, and
retinal dysplasia. There is a high mortality rate, approaching 80
percent in puppies less than one week old, and death usually occurs in
one to two days.
In puppies three to five weeks old, the
disease is less severe due to their ability to properly maintain body
temperature and mount a febrile response. More puppies survive, but
they can develop a latent infection. Some later get neurologic disease
and have symptoms like difficulty walking and blindness. Reactivation
of a latent infection may be caused by stress or immunosuppressive
drugs such as corticosteroids. The site of latency has been shown to
be the trigeminal ganglion and possibly the lumbosacral ganglion.
CHV In Adult Dogs In adult dogs, the virus infects the
reproductive tract, which allows it to be sexually transmitted or
passed to puppies during birth. The disease can cause abortion,
stillbirths, and infertility. It is also an infrequent cause of kennel
cough. Like other types of herpesvirus, previously infected dogs can
from time to time release the virus in vaginal secretions, penile
secretions, and discharge from the nose. Raised sores in the vagina or
on the penis may be seen during these times. Spread of the disease is
controlled by not breeding dogs known to have it. Serology can show
what dogs have been exposed (although not all of them will be
releasing the virus at that time). Serological studies of various dog
populations have revealed a seroprevalence of 40 to 93 percent.
Bitches who have a negative serology for CHV should be isolated from
other dogs from three weeks before to three weeks after giving birth.
Bitches that have lost puppies to the disease may have future litters
that survive due to transfer of antibodies in the milk.
Diagnosis, Treatment, and Control Diagnosis of the disease in puppies is best
accomplished by autopsy. Findings include hemorrhages in the kidneys,
liver, lungs, and gastrointestinal tract. Treatment of affected
puppies is difficult, although injecting antibodies of CHV into the
abdomen may help some to survive. Keeping the puppies warm is also
important. The virus does not survive well outside of the body and is
easily destroyed by most detergents. A vaccine in Europe known as
Eurican Herpes 205 has been available since 2003. It is given to the
dam (mother) twice: during heat or early pregnancy and one to two
weeks before whelping.